Dr. Renu Shrivastav

MINOR RESEARCH PROJECT 2013-14
FUNDED BY UGC

TOPIC
Toxicological impact of Bisphenal A on reproductive and endocrine physiology of male mice Mus Musculus.
Fund Granted : Rs. 1,50,000/-.

 

Executive Summary:
Bisphenol – A (BPA) is synthetic chemicals which are used in chemicals industry, the iron Metal industry, building and construction industry, plastic industry and the service industry. It is used to make baby bottle, food storage containers, kitchen appliances, beer and soft drink cans, in medical devices, dental sealants, electronics and automotive parts. BPA effects on liver, kidney, spleen, pancreas and reproductive organs BPA is associated early on- set puberty, disruption to growth hormones and developmental programming, type of cancer, disruptions to genes expression , changes in external behavior, memory loss, testosterone, male sexual dysfunction, heart disease, brain function, impaired nervous  system developments, liver damage, asthma, interfere with the immune system etc.
In the present study, 60 adult male mice (Musmusculus) weighing 35±5gwere brought to Laboratory of Endocrinology, Department of Biosciences. They were well maintained in the animal house at room temperature. All animals were divided into two groups. Group-I 10 mice served as control, while Group-II 30 mice was supplemented through alternate day orally (0.1ml/mice) for 15, 30 and 60 days.  These animals sacrificed on 16th, 31th, and 61th day respectively to evaluate the GSI weight, hormonal estimation, sperm analysis and histopathological changes occurred in testis, epididymis, vas deferens. Liver kidney were used  for  biochemical study- protein estimation, cholesterol estimation and enzymological study- glutamate oxyaloacetate transaminase (GOT), glutamate pyruvate transaminase level (GPT). Liver kidney tissue was quickly removed after sacrificing the animal, for biochemical and enzymological study.
Body weight and GSI values showed significantly changes in animals after BPA exposures up to 15, 30 and 60 days as compared to control group. It has been also observed that the BPA toxicity was significantly decreased sperm motility and sperm count after 15 and 30 days of exposure. While, it was more significantly effective in the later part of experiment i.e. 60 days. In morphologically studies of sperm noticed reduced percentage of normal sperm with abnormal structures characterizing by pin head, large head, oval head, and head less, bend neck, looping mid piece, coiled tail, double tail, tail less in BPA treated animals. Along with this, it has been noticed that BPA showed significantly decreased FSH, LH and Testosterones concentration is as compared to control in all the different duration of experiment.
In histopathological studies, BPA induced changes in seminiferous tubules with degeneration of spermatogenic cells and atrophy of leyding cells in testis after15, 30 and 60 days. These changes were more severe in the later part of experiment. Lumens were completely devoid of sperm after 60 days of BPA treated groups. In connection to this, cauda epididymis treated with BPA revealed thin walled tubules with disrupted muscle fibers and few spermatozoa in the lumens. These changes were more significant in the later part of experiment i.e. 60 days of BPA treatment.  Apart from this, the animals treated with BPA for 15, 30 days showed degenerative changes in vas deferens with degenerative changes of epithelium, less stereocilia and pycknotic nuclei. Whereas, these changes were more severe characterized by loss of stereocilia after 60 days of BPA treatment.
Result shows that there has been significant change in different parameter in this whole investigation. Mice treated with BPA cause no significant in the body weight, cholesterol level, organ weight and decrease in protein, result also shows that there has been significant increase in WBC and decrease in Hb% and RBC in 15 days. There is further significant increase in the body weight, cholesterol level, organ weight, WBC, and decrease in protein, Hb%, and RBC that were sacrificed after 30 days and 60 days. Mice treated with BPA   only showed a significant increase in body weight.
 Proteins are biochemical compound consisting of one are more polypeptide typically folded into globular or fibrous from in biological function way they are the building block, which are an essential constituent of food of animals. The protein concentration is highly reduced by BPA treatment in that investigation.
The data of the present study summarized as, the oral administration of BPA do not significantly affected to the body weight, increasing in body weight may be the affect of type of feed using during the experiment. After 15 day, 30 days and 60 days there was significant increase in GOT,GPT. There was further significant increase in GOT, GPT, in mice exposed to Bisphenol-A after 30 day and 60 days. Mice treated with BPA   only cause a significant increase in the total count of WBC, and decrease in, Hb%, and RBC, The protein concentration is highly reduced by BPA treatment after 15 days. Protein content of liver and kidney tissues were chronologically decreased after treatment with BPA in that investigation. Cholesterol content of liver and kidney tissues were chronologically decreased after treatment with BPA.
For histopathological study thyroid, liver, kidney and adrenal were dissected out quickly and placed in the vials containing Bouin’s fixative and were subjected to fixation for minimum 48 to 72 hours. Then embedded in paraffin wax and sectioned (5-7µm thick) by using a rotary microtome. Sections were stained in Hematoxyline-Eosin stain and phtomicrograps were prepared (H&E 100x and 400x).
In our study histopathological studies have been also showed that Bisphenol-A induced degenerative changes and vacuolization in hepatic cells after 15,30 and 60 days as compared to control. Histopathological studies show that the liver and kidney were affected by Bisphenol-A exposure.  Morphological degeneration in the liver and kidney were observed after 15 and 30 days of BPA exposure in Musmusculus.
BPA changes in thyroid as well as in adrenal gland after 15,30 and 60 days showed necrosis in parenchymal cells and lymphocytic infiltration.  However, the effects were less documented in 15, 30 and 60 days treated thyroid.  This indicates that BPA effects duration dependent and we can also concluded that BPA modulates the thyroid activity by affecting directly on the tissue or through hypothalamo-hypophsealthroid axis.  Moreover BPA also caused changes in adrenal glands after 15, 30 and 60 days characterized by the dengenerating and pycnotic cells in all the three regions of the adrenal gland and medullary cells. Above data conclude that BPA inhibits and function of thyroid and adrenal gland may be directly or through positive and negative feed back mechanism.
According to all above finding, we can conclude that BPA caused descriptive damages in the development and function of male reproductive system by affecting fertility rate, lowering sperm count and motility. BPA also modulated hormonal and histopathological changes in testis, epididymis, vas deferens , adrenal, thyroid, liver and kidney of male mice (Musmusculus). All these changes are dose and duration dependents. BPA either affecter directly on the hypothalamus hypophyseal gonadal axis by modulating circulating gonadotrophic hormones i.e. FSH and LH levels in the blood. Lastly we may also conclude that Bisphenol-A may caused these effects directly on the glands and reproductive organs in male mice Musmusculus.